Prototaxites not animal, vegetable or fungus (maybe)

 

You said:

Several years ago an acquaintance told me we don't really know what Prototaxities is, so we say its a fungus.

ChatGPT said:

Yes, that’s basically correct. Prototaxites (the spelling more commonly used now) is one of those puzzling fossils from the Late Silurian to Late Devonian periods, roughly 420–370 million years ago. They were huge—tree-like in size, sometimes over 8 meters tall—but the debate about what they actually were has been ongoing for decades.

Initially, paleontologists thought they might be giant early conifers because of their vertical, branching structures, hence the “taxites” in the name suggesting a conifer relation. But later chemical and microscopic analysis suggested a fungal nature—mainly because the tissues resembled fungal hyphae rather than plant vascular tissue. So today, the consensus leans toward a massive fungus (or possibly a lichen-like symbiosis with cyanobacteria), but it’s not 100% settled. The fossils are fragmentary, and without living analogs, we can’t be entirely certain.

It’s a fascinating example of how something can look “tree-like” but turn out to be something very different—a true ancient botanical mystery.

If you want, I can explain why scientists favor the fungal interpretation over a plant one; it’s pretty neat. Do you want me to?

You said:

Several news items today suggest it may not be animal, nor vegetable, nor fungus but a different and now extinct life form.

ChatGPT said:

Yes — the recent news you’re seeing is all about new scientific research suggesting that Prototaxites might not fit neatly into any modern group like plants, animals, or fungi, but instead belongs to an extinct, completely unique branch of life. This is a big shift in how scientists describe it.

Here’s what’s going on:

🔬 Old views vs. new research

Traditionally, Prototaxites — these huge, column‑like fossils from the Silurian and Devonian periods (roughly 420–375 million years ago) — were often interpreted as giant fungi or possibly a fungus‑like organism. For over a century that was one of the dominant hypotheses because its tube‑like internal structure superficially resembles fungal hyphae.

🧪 What the newest study found

A 2026 paper in the journal Science Advances examined exceptionally well‑preserved Prototaxites taiti fossils from the Rhynie Chert (an ancient fossil site in Scotland) using advanced imaging and chemical analysis. The study found:

• The internal anatomy has a complex network of different kinds of tubes that doesn’t match what we see in fungi.

• The chemical signature of the fossil lacked detectable chitin (a molecule found in all fungi) and differed from fossilized fungi found in the same rocks.

• When compared with known organisms, Prototaxites didn’t match any existing group of plants, animals, or fungi.

Because of these distinctive structural and chemical traits, the researchers argue that Prototaxites most likely belonged to an entire eukaryotic lineage that no longer exists today — effectively a dead branch of complex life separate from the kingdoms we know.

🧬 What this means

So rather than being confidently labeled a fungus (which was always a plausible but debated option), the organism may now be better described as part of a unique, extinct group of multicellular life — something that doesn’t fit comfortably into the plant, animal, or fungus kingdoms. Many scientists describe this as a “new branch” or “independent experiment” in complex life.

That said, this isn’t a finished chapter — further research and fossil evidence will help confirm or refine these conclusions. At the moment, the best summary is that Prototaxites is an enigmatic organism that challenges our traditional categories of life.

If you want, I can break down a bit more about what made researchers think it was a fungus before, and why that idea is weaker now. Want that?

You said:

This is multicellular life on land; there must be a long if now unseen history.

ChatGPT said:

Exactly—that’s one of the most fascinating implications. Prototaxites wasn’t just some tiny, marginal organism; it was a massive multicellular life form dominating terrestrial ecosystems hundreds of millions of years ago, long before large trees or forests appeared. Some of the tallest specimens were over 8 meters high, making them the largest land organisms of their time, long before the rise of true vascular plants.

This suggests a couple of things about early land life:

1. Terrestrial ecosystems were already complex. Even though plants were still relatively small, there were enough microbes, fungi, and tiny plants to support a massive, probably saprotrophic (decomposer‑like) organism. Prototaxites may have formed the ecological backbone of its environment, shaping soil, moisture, and nutrient cycles.

2. There must have been a long evolutionary history we barely see. Fossilization favors hard parts like bones or wood. Prototaxites, like fungi and many soft-bodied organisms, left mostly ephemeral traces. Its appearance in the Silurian–Devonian suggests its lineage had been evolving for tens of millions of years before we find it in the fossil record. Essentially, there’s a hidden history of multicellular life on land that’s mostly invisible to us today.

3. A distinct evolutionary experiment. If this was neither plant, fungus, nor animal, it represents a now-extinct branch of eukaryotic life—a successful experiment in being a giant terrestrial organism that eventually went extinct, leaving almost no trace except these towering fossils.

It’s humbling to realize that the land was dominated by life forms that had nothing like today’s trees or fungi, and that there are entire lineages of multicellular life we’ll never see again. In some ways, Prototaxites is a window into a lost world, a reminder that what survives in fossils is only a tiny fraction of what once existed.

If you like, I can sketch a timeline of land life showing where Prototaxites fits and what else existed around it—it really emphasizes how alien its world was. Do you want me to do that?

You said:

Animals eat plants and each other, plants eat sunshine, fungi eat decaying matter. What's left?

ChatGPT said:

Exactly—that’s the puzzle that makes Prototaxites so intriguing. In modern ecosystems, almost everything falls into one of those three categories: autotrophs (plants, algae, some bacteria), heterotrophs that consume organic matter (animals), and decomposers (fungi and many microbes). But Prototaxites seems to defy that classification.

From the fossils we have, scientists think it was probably a heterotroph of some kind—it likely absorbed nutrients from its surroundings—but not like a modern fungus or animal. Its internal structure suggests it could transport nutrients throughout its massive body, maybe feeding on microbial mats, decaying plant matter, or symbiotic partners, but not “photosynthesizing” like plants. In other words, it was doing something novel: a gigantic, multicellular organism on land that was neither eating sunlight, living prey, nor strictly decomposing.

You could imagine it as an ancient, top‑level recycler of nutrients, a kind of “ecosystem scaffold” that doesn’t exist today. It dominated the land not by competing with plants or animals but by exploiting a niche that modern kingdoms already claim in different ways.

So, to your question: what’s left? Something like Prototaxites—a unique branch of life that solved the problem of land-based survival in a way we no longer see on Earth. It’s like looking at an extinct ecosystem and realizing that our modern categories—plant, animal, fungus—only cover part of what life once experimented with.

If you want, I can outline the possible “what it ate and how it lived” scenarios, based on the latest research—it’s surprisingly plausible even if alien. Do you want me to do that?